1. Field of the Invention
The present invention relates to a colored curable composition, a color filter and a production method thereof, and a solid-state imaging device.
2. Description of the Related Art
Color filters are an indispensable part of liquid crystal displays (LCDs) and solid-state imaging devices.
These color filters have color patterns of multiple hues and usually have colored regions of at least red, green and blue colors (hereinafter, also called “color patterns” or “colored pixels”). A method for forming such a color filter is as follows. First, a curable composition containing any one of red, green and blue colorants is applied by coating to provide a first hue, and the curable composition is then exposed to light and developed, and subjected to a heat treatment as needed, to form a color pattern having the first hue. Next, similar coating, exposure and development processes, and a heat treatment as needed, are repeated with respect to a second hue and a third hue, respectively.
Recently, for both liquid crystal displays and solid-state imaging devices, the formation of fine color patterns (for example, color patterns having a side of 2.0 μm or less) with good reproducibility is demanded to improve resolving power, and a reduction in the thickness of a thin film of a color pattern (for example, to 1 μm or less) is also demanded.
In solid-state imaging devices that use a color filter having the aforementioned fine color patterns, color reproducibility and noise caused by color mixing are problematic, and, it is known that, particularly in a red filter, a local increase in transmittance near 530 nm causes degradation of image quality.
In order to suppress the local increase in transmittance near 530 nm, a technique of using Pigment Orange 38 (PO 38) or the like has been developed (see, for example, Japanese Patent Application Lai-Open (JP-A) No. 2001-154011).
However, even when the technique described in JP-A No. 2001-154011 is used, it is not possible to form a pattern with a small area having a side of 2.0 μm or less, and achieve dispersion uniformity and stable long term viscosity of a composition.
Accordingly, in the field of colored curable compositions, a curable composition is desired which imparts transmittance to color filters, in particular, color filters for solid-state imaging devices, and which has excellent dispersion uniformity, long-term viscosity stability, and good development properties, and is suitable for forming images having a small area.